叶酸受体1在鼻咽癌细胞抵抗紫杉醇化疗药物中的作用

目的 研究叶酸受体1(folate receptor 1,FOLR1)在鼻咽癌细胞和永生化正常鼻咽细胞(NP69)中表达的差异,及FOLR1的表达与鼻咽癌紫杉醇耐药的相关性,为FOLR1介导的肿瘤靶向治疗及耐药逆转提供实验依据.方法 利用基因芯片技术,反转录聚合酶链反应(RT-PCR),Western blot和免疫细胞化学技术检测FOLR1在永生化正常鼻咽细胞(NP69),鼻咽癌细胞系(CNE-1)及紫杉醇耐药细胞系(CNE-1/Taxol)中表达的差异;利用小干扰RNA(siRNA)技术抑制CNE-1/Taxol中FOLR1的表达后,观察其耐药能否逆转.结果 基因芯片结果 显示CNE-1/Taxol中FOLR1的表达为2636.0,CNE-1的表达为176.0;RT-PCR和Western blot结果 显示FOLR1在NP69中无表达,而在CNE-1及CNE-1/Taxol中呈阳性表达,并且与耐药指数呈正相关(r2=0.8719);免疫细胞化学结果 也证实了FOLR1在鼻咽癌CNE-1/Taxol中高表达;利用siRNA技术抑制CNE-1/Taxol中FOLR1的表达后,耐药细胞对紫杉醇的敏感性显著增加,其IC50值降低了59.6%(t=6.92,P<0.001).结论 实验结果 提示FOLR1的表达与鼻咽癌发生及紫杉醇耐药密切相关.FOLR1基因将可能成为鼻咽癌治疗及紫杉醇耐约逆转的靶分子之一.

Role of folate receptor 1 in paclitaxol-resistance of nasopharyngeal carcinoma cells

Objective To provide experimental evidence for the folate receptor 1 (FOLR1)mediated targeted cancer therapy and resistance reversal, the FOLR1 expression differences in nasopharyngeal carcinoma cells (CNE-1) and immortalized normal nasopharyngeal cells (NP69) and the correlation between FOLR1 expression and paclitaxel resistance index in nasopharyngeal carcinoma were investigated. Methods The expressions of FOLR1 in CNE-1, CNE-1/Taxol (paclitaxel-resistance cells)and NP69 was detected by cDNA microarray, reverse transcriptase-polymerase chain reaction(RT-PCR),Western blot and immunocytochemistry. Proliferation inhibition rates of CNE-1 and CNE-1/Taxol cells were measured by colony formation assay after treated by short interfering RNA (siRNA) of FOLR1. Results The expressions of FOLR1 gene in CNE-1/Taxol cells and CNE-1 cells were 2636.0 and 176. 0,respectively. The expression of FOLR1 was not detected in the NP69 by semi-quantative RT-PCR and Western blot. The high expression of FOLR1 in CNE-1/Taxol was verified by semi-quantative RT-PCR, and its expression level was positively correlated to the degree of drug-resistance(r2 =0. 8719). The results were also validated by Western blot and immunocytochemistry. The sensitivity of CNE-1/Taxol to paclitaxel significantly increased after inhibition of FOLR1 gene expression by siRNA, and its IC50 value was decreased by 59. 6% (t = 6. 92, P < 0. 01). Conclusions The expression of FOLR1 is closely related to the occurrence of NPC and Taxol resistance. FOLR1 gene may be one of the important target molecules in NPC treatment and reversion of the paclitaxel-resistance in NPC.